JS Client for DAML Ledger API (REST)

Introduction

This JS client assumes that DAML Ledger API (v1) (gRPC) is already being proxied by gRPC-gateway service into HTTP server (quasi-REST, only through POST with JSON arguments).

(Docker service for the proxy service can be found here with launch instructions. If you already have Docker installed in your environment, you can run this reverse proxy service in two commands.)

DAML Ledger API uses proto files to auto-generate the gRPC service endpoint, which are defined in DAML's official repo.

(Although auto-generation of JS client from proto files can be done through gRPC Web, it is still very difficult and unstable (as of 8/30/2019) to go this route to access gRPC directly. This is true for both node.js and in-browser; I have tried for many hours with no success.)

General Usage

1const LAPI = require('@vmw-jkk/daml-lapi-rest');
2
3//Test execute in async context for easier flow
4LAPI.do = async function(){
5    try{
6
7        LAPI.setVerbose(1);
8        await LAPI.setEndpoint('http://localhost:7865');
9        await LAPI.autoSetLedgerId(); //Auto Sets Ledger API
10
11    }
12    catch(e){ console.log(e) }
13}
14

Eventual Upgrades

The most graceful solution would be that DAML Ledger API natively supporting REST API, out-of-box. However, as of 8/30/2019, no such support is due in the foreseable future.

When DAML Ledger API supports REST, this library won't be necessary as most services in most languages can easily interact with REST, and will have no problem easily scaling up from that point.

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Resources

There are many components working together in this library. All components with their documentations are compiled below:

• Useful Resources

Reported Issues

None so far.

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License

Copyright 2019 VMware, all rights reserved.
(Applied only to original code sections specified in the files)

Collaborators

Joe K. Kim @ VMware / Blockchain Team